Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
N Engl J Med ; 387(8): 679-691, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-35866746

RESUMO

BACKGROUND: Before April 2022, monkeypox virus infection in humans was seldom reported outside African regions where it is endemic. Currently, cases are occurring worldwide. Transmission, risk factors, clinical presentation, and outcomes of infection are poorly defined. METHODS: We formed an international collaborative group of clinicians who contributed to an international case series to describe the presentation, clinical course, and outcomes of polymerase-chain-reaction-confirmed monkeypox virus infections. RESULTS: We report 528 infections diagnosed between April 27 and June 24, 2022, at 43 sites in 16 countries. Overall, 98% of the persons with infection were gay or bisexual men, 75% were White, and 41% had human immunodeficiency virus infection; the median age was 38 years. Transmission was suspected to have occurred through sexual activity in 95% of the persons with infection. In this case series, 95% of the persons presented with a rash (with 64% having ≤10 lesions), 73% had anogenital lesions, and 41% had mucosal lesions (with 54 having a single genital lesion). Common systemic features preceding the rash included fever (62%), lethargy (41%), myalgia (31%), and headache (27%); lymphadenopathy was also common (reported in 56%). Concomitant sexually transmitted infections were reported in 109 of 377 persons (29%) who were tested. Among the 23 persons with a clear exposure history, the median incubation period was 7 days (range, 3 to 20). Monkeypox virus DNA was detected in 29 of the 32 persons in whom seminal fluid was analyzed. Antiviral treatment was given to 5% of the persons overall, and 70 (13%) were hospitalized; the reasons for hospitalization were pain management, mostly for severe anorectal pain (21 persons); soft-tissue superinfection (18); pharyngitis limiting oral intake (5); eye lesions (2); acute kidney injury (2); myocarditis (2); and infection-control purposes (13). No deaths were reported. CONCLUSIONS: In this case series, monkeypox manifested with a variety of dermatologic and systemic clinical findings. The simultaneous identification of cases outside areas where monkeypox has traditionally been endemic highlights the need for rapid identification and diagnosis of cases to contain further community spread.


Assuntos
Saúde Global , Mpox , Adulto , Exantema/etiologia , Feminino , Febre/etiologia , Saúde Global/estatística & dados numéricos , Humanos , Masculino , Mpox/epidemiologia , Mpox/terapia , Monkeypox virus
2.
J Clin Microbiol ; 62(3): e0151823, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38299828

RESUMO

Broad-range 16S rRNA PCR and sequencing of 1,183 blood specimens from 853 unique patients yielded an interpretable sequence and bacterial identification in 29%, 16S rRNA amplification with uninterpretable sequences in 53%, and no amplification in 18%. This study highlights the potential utility of this technique in identifying fastidious gram-negative and anaerobic bacteria but the frequent recovery of environmental and contaminant organisms argues for its judicious use. IMPORTANCE: The existing literature focuses on its performance compared to blood cultures in patients with sepsis, leaving a gap in the literature regarding other blood specimens in suspected infectious syndrome across the severity spectrum. We aimed to characterize its microbiological outcomes and provide insight into its potential clinical utility.


Assuntos
RNA Ribossômico 16S , Humanos , RNA Ribossômico 16S/genética , Estudos Retrospectivos , DNA Bacteriano/genética , Reação em Cadeia da Polimerase/métodos , Canadá , Análise de Sequência de DNA
3.
Ann Intern Med ; 176(1): 67-76, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36508736

RESUMO

BACKGROUND: Monkeypox, a viral zoonotic disease, is causing a global outbreak outside of endemic areas. OBJECTIVE: To characterize the outbreak of monkeypox in Montréal, the first large outbreak in North America. DESIGN: Epidemiologic and laboratory surveillance data and a phylogenomic analysis were used to describe and place the outbreak in a global context. SETTING: Montréal, Canada. PATIENTS: Probable or confirmed cases of monkeypox. MEASUREMENTS: Epidemiologic, clinical, and demographic data were aggregated. Whole-genome sequencing and phylogenetic analysis were performed for a set of outbreak sequences. The public health response and its evolution are described. RESULTS: Up to 18 October 2022, a total of 402 cases of monkeypox were reported mostly among men who have sex with men (MSM), most of which were suspected to be acquired through sexual contact. All monkeypox genomes nested within the B.1 lineage. Montréal Public Health worked closely with the affected communities to control the outbreak, becoming the first jurisdiction to offer 1 dose of the Modified Vaccinia Ankara-Bavarian Nordic vaccine as preexposure prophylaxis (PrEP) to those at risk in early June 2022. Two peaks of cases were seen in early June and July (43 and 44 cases per week, respectively) followed by a decline toward near resolution of the outbreak in October. Reasons for the biphasic peak are not fully elucidated but may represent the tempo of vaccination and/or several factors related to transmission dynamics and case ascertainment. LIMITATIONS: Clinical data are self-reported. Limited divergence among sequences limited genomic epidemiologic conclusions. CONCLUSION: A large outbreak of monkeypox occurred in Montréal, primarily among MSM. Successful control of the outbreak rested on early and sustained engagement with the affected communities and rapid offer of PrEP vaccination to at-risk persons. PRIMARY FUNDING SOURCE: None.


Assuntos
Mpox , Minorias Sexuais e de Gênero , Masculino , Humanos , Filogenia , Homossexualidade Masculina , Mpox/epidemiologia , Surtos de Doenças , América do Norte/epidemiologia , Autorrelato
4.
Environ Sci Technol ; 57(49): 20559-20570, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38019974

RESUMO

Marine cloud brightening (MCB) is a potential intervention to mitigate the effects of climate change by increasing the reflectance of low-level maritime clouds, including those over the Great Barrier Reef. The technique involves dispersing a plume of submicrometer seawater droplets over the ocean, which evaporate, generating nanosized sea-salt aerosols (SSAs) that disperse through the atmosphere with some fraction incorporated into clouds. Droplet evaporation, which occurs in the immediate vicinity (meters to tens of meters) of the source, has been theorized to produce a negatively buoyant plume hindering the mixing of the sea-salt aerosol to cloud height and compromising the effectiveness of MCB. We characterized in situ for the first time the nearfield aerosol dispersion from a point source of atomized seawater produced using the effervescent technique. We observed consistent vertical mixing of the plume up to 150 ± 5 m height at 1 km downwind. The extent of vertical dispersion was influenced by wind velocity and atmospheric stability. We found no evidence that negative buoyancy due to the evaporation of the 0.068 kg/s water fraction significantly suppressed vertical mixing. Our results can be attributed to the small droplet sizes generated by the effervescent spray technology and associated low flow rates required to generate around 1014 droplets s-1. We estimate that, for a hypothetical implementation producing up to 1016 s-1 similarly sized SSAs, evaporative cooling is unlikely to significantly suppress the vertical dispersion of aerosol for MCB.


Assuntos
Atmosfera , Água do Mar , Água , Vento , Aerossóis/análise
5.
Emerg Infect Dis ; 28(12): 2567-2569, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36418003

RESUMO

Prolonged eosinophilia is characteristic of trichinellosis. To determine the optimal eosinophil threshold for reflex Trichinella testing, we examined all 43 cases in Nunavik, Quebec, Canada, during 2009-2019. Using receiver operating characteristic analysis, we determined that eosinophil counts >0.8 × 109 cells/L should prompt consideration of trichinellosis and testing to rapidly identify potential outbreaks.


Assuntos
Eosinofilia , Trichinella , Triquinelose , Animais , Quebeque/epidemiologia , Triquinelose/diagnóstico , Triquinelose/epidemiologia , Canadá , Eosinofilia/diagnóstico , Eosinofilia/epidemiologia
6.
J Clin Microbiol ; 60(1): e0171721, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34669455

RESUMO

We aimed to assess the specificity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody detection assays among people with tissue-borne parasitic infections. We tested three SARS-CoV-2 antibody-detection assays (cPass SARS-CoV-2 neutralization antibody detection kit [cPass], Abbott SARS-CoV-2 IgG assay [Abbott Architect], and Standard Q COVID-19 IgM/IgG combo rapid diagnostic test [SD RDT IgM/SD RDT IgG]) among 559 pre-COVID-19 seropositive sera for several parasitic infections. The specificity of assays was 95 to 98% overall. However, lower specificity was observed among sera from patients with protozoan infections of the reticuloendothelial system, such as human African trypanosomiasis (Abbott Architect; 88% [95% CI, 75 to 95]) and visceral leishmaniasis (SD RDT IgG; 80% [95% CI, 30 to 99]), and from patients with recent malaria in areas of Senegal where malaria is holoendemic (ranging from 91% for Abbott Architect and SD RDT IgM to 98 to 99% for cPass and SD RDT IgG). For specimens from patients with evidence of past or present helminth infection overall, test specificity estimates were all ≥96%. Sera collected from patients clinically suspected of parasitic infections that tested negative for these infections yielded a specificity of 98 to 100%. The majority (>85%) of false-positive results were positive by only one assay. The specificity of SARS-CoV-2 serological assays among sera from patients with tissue-borne parasitic infections was below the threshold required for decisions about individual patient care. Specificity is markedly increased by the use of confirmatory testing with a second assay. Finally, the SD RDT IgG proved similarly specific to laboratory-based assays and provides an option in low-resource settings when detection of anti-SARS-CoV-2 IgG is indicated.


Assuntos
COVID-19 , Helmintos , Doenças Parasitárias , Animais , Anticorpos Antivirais , Humanos , Imunoglobulina M , SARS-CoV-2 , Sensibilidade e Especificidade , Testes Sorológicos
7.
CMAJ ; 194(7): E242-E251, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35045989

RESUMO

BACKGROUND: The role of remdesivir in the treatment of patients in hospital with COVID-19 remains ill defined in a global context. The World Health Organization Solidarity randomized controlled trial (RCT) evaluated remdesivir in patients across many countries, with Canada enrolling patients using an expanded data collection format in the Canadian Treatments for COVID-19 (CATCO) trial. We report on the Canadian findings, with additional demographics, characteristics and clinical outcomes, to explore the potential for differential effects across different health care systems. METHODS: We performed an open-label, pragmatic RCT in Canadian hospitals, in conjunction with the Solidarity trial. We randomized patients to 10 days of remdesivir (200 mg intravenously [IV] on day 0, followed by 100 mg IV daily), plus standard care, or standard care alone. The primary outcome was in-hospital mortality. Secondary outcomes included changes in clinical severity, oxygen- and ventilator-free days (at 28 d), incidence of new oxygen or mechanical ventilation use, duration of hospital stay, and adverse event rates. We performed a priori subgroup analyses according to duration of symptoms before enrolment, age, sex and severity of symptoms on presentation. RESULTS: Across 52 Canadian hospitals, we randomized 1282 patients between Aug. 14, 2020, and Apr. 1, 2021, to remdesivir (n = 634) or standard of care (n = 648). Of these, 15 withdrew consent or were still in hospital, for a total sample of 1267 patients. Among patients assigned to receive remdesivir, in-hospital mortality was 18.7%, compared with 22.6% in the standard-of-care arm (relative risk [RR] 0.83 (95% confidence interval [CI] 0.67 to 1.03), and 60-day mortality was 24.8% and 28.2%, respectively (95% CI 0.72 to 1.07). For patients not mechanically ventilated at baseline, the need for mechanical ventilation was 8.0% in those assigned remdesivir, and 15.0% in those receiving standard of care (RR 0.53, 95% CI 0.38 to 0.75). Mean oxygen-free and ventilator-free days at day 28 were 15.9 (± standard deviation [SD] 10.5) and 21.4 (± SD 11.3) in those receiving remdesivir and 14.2 (± SD 11) and 19.5 (± SD 12.3) in those receiving standard of care (p = 0.006 and 0.007, respectively). There was no difference in safety events of new dialysis, change in creatinine, or new hepatic dysfunction between the 2 groups. INTERPRETATION: Remdesivir, when compared with standard of care, has a modest but significant effect on outcomes important to patients and health systems, such as the need for mechanical ventilation. Trial registration: ClinicalTrials.gov, no. NCT04330690.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/administração & dosagem , Tratamento Farmacológico da COVID-19 , Mortalidade Hospitalar , Tempo de Internação/estatística & dados numéricos , Monofosfato de Adenosina/administração & dosagem , Monofosfato de Adenosina/efeitos adversos , Idoso , Alanina/administração & dosagem , Alanina/efeitos adversos , Antivirais/efeitos adversos , COVID-19/epidemiologia , COVID-19/mortalidade , Canadá/epidemiologia , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Respiração Artificial/estatística & dados numéricos , SARS-CoV-2
9.
Eur J Neurosci ; 51(11): 2219-2235, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31919899

RESUMO

Germline mutations in the basic helix-loop-helix transcription factor 4 (TCF4) cause the Pitt-Hopkins syndrome (PTHS), a developmental disorder with severe intellectual disability. Here, we report findings from a new mouse model with a central nervous system-specific truncation of Tcf4 leading to severe phenotypic abnormalities. Furthermore, it allows the study of a complete TCF4 knockout in adult mice, circumventing early postnatal lethality of previously published mouse models. Our data suggest that a TCF4 truncation results in an impaired hippocampal architecture affecting both the dentate gyrus as well as the cornu ammonis. In the cerebral cortex, loss of TCF4 generates a severe differentiation delay of neural precursors. Furthermore, neuronal morphology was critically affected with shortened apical dendrites and significantly increased branching of dendrites. Our data provide novel information about the role of Tcf4 in brain development and may help to understand the mechanisms leading to intellectual deficits observed in patients suffering from PTHS.


Assuntos
Hiperventilação , Deficiência Intelectual , Fator de Transcrição 4 , Animais , Fácies , Hipocampo , Humanos , Deficiência Intelectual/genética , Camundongos , Neurônios , Fator de Transcrição 4/genética
10.
Int J Obes (Lond) ; 43(6): 1305-1318, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30283080

RESUMO

BACKGROUND/OBJECTIVES: Individuals carrying loss-of-function gene mutations for the adipocyte hormone leptin are morbidly obese, but respond favorably to replacement therapy. Recombinant leptin is however largely ineffective for the vast majority of obese individuals due to leptin resistance. One theory underlying leptin resistance is impaired leptin transport across the blood-brain-barrier (BBB). Here, we aim to gain new insights into the mechanisms of leptin BBB transport, and its role in leptin resistance. METHODS: We developed a novel tool for visualizing leptin transport using infrared fluorescently labeled leptin, combined with tissue clearing and light-sheet fluorescence microscopy. We corroborated these data using western blotting. RESULTS: Using 3D whole brain imaging, we display comparable leptin accumulation in circumventricular organs of lean and obese mice, predominantly in the choroid plexus (CP). Protein quantification revealed comparable leptin levels in microdissected mediobasal hypothalami (MBH) of lean and obese mice (p = 0.99). We further found increased leptin receptor expression in the CP (p = 0.025, p = 0.0002) and a trend toward elevated leptin protein levels in the MBH (p = 0.17, p = 0.078) of obese mice undergoing weight loss interventions by calorie restriction or exendin-4 treatment. CONCLUSIONS: Overall, our findings suggest a crucial role for the CP in controlling the transport of leptin into the cerebrospinal fluid and from there to target areas such as the MBH, potentially mediated via the leptin receptor. Similar leptin levels in circumventricular organs and the MBH of lean and obese mice further suggest intact leptin BBB transport in leptin resistant mice.


Assuntos
Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Leptina/metabolismo , Camundongos Obesos/metabolismo , Obesidade Mórbida/metabolismo , Animais , Transporte Biológico , Barreira Hematoencefálica/diagnóstico por imagem , Western Blotting , Encéfalo/diagnóstico por imagem , Modelos Animais de Doenças , Fluorescência , Células HEK293 , Humanos , Imageamento Tridimensional , Camundongos , Imagem Molecular
11.
Acta Neuropathol ; 137(4): 657-673, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30830316

RESUMO

The TCF4 gene encodes for the basic helix-loop-helix transcription factor 4 (TCF4), which plays an important role in the development of the central nervous system (CNS). Haploinsufficiency of TCF4 was found to cause Pitt-Hopkins syndrome (PTHS), a severe neurodevelopmental disorder. Recently, the screening of a large cohort of medulloblastoma (MB), a highly aggressive embryonal brain tumor, revealed almost 20% of adult patients with MB of the Sonic hedgehog (SHH) subtype carrying somatic TCF4 mutations. Interestingly, many of these mutations have previously been detected as germline mutations in patients with PTHS. We show here that overexpression of wild-type TCF4 in vitro significantly suppresses cell proliferation in MB cells, whereas mutant TCF4 proteins do not to the same extent. Furthermore, RNA sequencing revealed significant upregulation of multiple well-known tumor suppressors upon expression of wild-type TCF4. In vivo, a prenatal knockout of Tcf4 in mice caused a significant increase in apoptosis accompanied by a decreased proliferation and failed migration of cerebellar granule neuron precursor cells (CGNP), which are thought to be the cells of origin for SHH MB. In contrast, postnatal in vitro and in vivo knockouts of Tcf4 with and without an additional constitutive activation of the SHH pathway led to significantly increased proliferation of CGNP or MB cells. Finally, publicly available data from human MB show that relatively low expression levels of TCF4 significantly correlate with a worse clinical outcome. These results not only point to time-specific roles of Tcf4 during cerebellar development but also suggest a functional linkage between TCF4 mutations and the formation of SHH MB, proposing that TCF4 acts as a tumor suppressor during postnatal stages of cerebellar development.


Assuntos
Proteínas Hedgehog/genética , Meduloblastoma/genética , Mutação , Fator de Transcrição 4/genética , Animais , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Fácies , Proteínas Hedgehog/metabolismo , Humanos , Hiperventilação/genética , Hiperventilação/metabolismo , Hiperventilação/patologia , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Meduloblastoma/metabolismo , Meduloblastoma/patologia , Camundongos , Camundongos Knockout , Fator de Transcrição 4/metabolismo
12.
J Neuroinflammation ; 15(1): 35, 2018 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-29422055

RESUMO

ᅟ: Astrocytosis is a reactive process involving cellular, molecular, and functional changes to facilitate neuronal survival, myelin preservation, blood brain barrier function and protective glial scar formation upon brain insult. The overall pro- or anti-inflammatory impact of reactive astrocytes appears to be driven in a context- and disease-driven manner by modulation of astrocytic Ca2+ homeostasis and activation of Ca2+/calmodulin-activated serine/threonine phosphatase calcineurin. Here, we aimed to assess whether calcineurin is dispensable for astrocytosis in the hypothalamus driven by prolonged high fat diet (HFD) feeding. Global deletion of calcineurin A beta (gene name: Ppp3cb) led to a decrease of glial fibrillary acidic protein (GFAP)-positive cells in the ventromedial hypothalamus (VMH), dorsomedial hypothalamus (DMH), and arcuate nucleus (ARC) of mice exposed chronically to HFD. The concomitant decrease in Iba1-positive microglia in the VMH further suggests a modest impact of Ppp3cb deletion on microgliosis. Pharmacological inhibition of calcineurin activity by Fk506 had no impact on IBA1-positive microglia in hypothalami of mice acutely exposed to HFD for 1 week. However, Fk506-treated mice displayed a decrease in GFAP levels in the ARC. In vivo effects could not be replicated in cell culture, where calcineurin inhibition by Fk506 had no effect on astrocytic morphology, astrocytic cell death, GFAP, and vimentin protein levels or microglia numbers in primary hypothalamic astrocytes and microglia co-cultures. Further, adenoviral overexpression of calcineurin subunit Ppp3r1 in primary glia culture did not lead to an increase in GFAP fluorescence intensity. Overall, our results point to a prominent role of calcineurin in mediating hypothalamic astrocytosis as response to acute and chronic HFD exposure. Moreover, discrepant findings in vivo and in cell culture indicate the necessity of studying astrocytes in their "natural" environment, i.e., preserving an intact hypothalamic microenvironment with neurons and non-neuronal cells in close proximity.


Assuntos
Calcineurina/deficiência , Dieta Hiperlipídica/efeitos adversos , Gliose/metabolismo , Gliose/prevenção & controle , Hipotálamo/metabolismo , Animais , Astrócitos/metabolismo , Sobrevivência Celular/fisiologia , Células Cultivadas , Gliose/patologia , Hipotálamo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
13.
J Nematol ; 49(4): 348-356, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29353922

RESUMO

The microbiome influences host processes including nutritional availability, development, immunity, and behavioral responses. Caenorhabditis elegans is a powerful model to study molecular mechanisms of host-microbial interactions. Recent efforts have been made to profile the natural microbiome of C. elegans, laying a foundation for mechanistic studies of host-microbiome interactions in this genetically tractable model system. Studies using single-species microbes, multi-microbial systems, and humanized worm-microbiome interaction studies reveal metabolic and microbial-microbial interactions relevant in higher organisms. This article discusses recent developments in modeling the effects of host-microbiome interactions in C. elegans.

14.
Syst Biol ; 64(2): 307-24, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25527198

RESUMO

Likelihood-based methods are commonplace in phylogenetic systematics. Although much effort has been directed toward likelihood-based models for molecular data, comparatively less work has addressed models for discrete morphological character (DMC) data. Among-character rate variation (ACRV) may confound phylogenetic analysis, but there have been few analyses of the magnitude and distribution of rate heterogeneity among DMCs. Using 76 data sets covering a range of plants, invertebrate, and vertebrate animals, we used a modified version of MrBayes to test equal, gamma-distributed and lognormally distributed models of ACRV, integrating across phylogenetic uncertainty using Bayesian model selection. We found that in approximately 80% of data sets, unequal-rates models outperformed equal-rates models, especially among larger data sets. Moreover, although most data sets were equivocal, more data sets favored the lognormal rate distribution relative to the gamma rate distribution, lending some support for more complex character correlations than in molecular data. Parsimony estimation of the underlying rate distributions in several data sets suggests that the lognormal distribution is preferred when there are many slowly evolving characters and fewer quickly evolving characters. The commonly adopted four rate category discrete approximation used for molecular data was found to be sufficient to approximate a gamma rate distribution with discrete characters. However, among the two data sets tested that favored a lognormal rate distribution, the continuous distribution was better approximated with at least eight discrete rate categories. Although the effect of rate model on the estimation of topology was difficult to assess across all data sets, it appeared relatively minor between the unequal-rates models for the one data set examined carefully. As in molecular analyses, we argue that researchers should test and adopt the most appropriate model of rate variation for the data set in question. As discrete characters are increasingly used in more sophisticated likelihood-based phylogenetic analyses, it is important that these studies be built on the most appropriate and carefully selected underlying models of evolution.


Assuntos
Invertebrados/classificação , Filogenia , Plantas/classificação , Vertebrados/classificação , Animais , Teorema de Bayes , Invertebrados/anatomia & histologia , Invertebrados/genética , Modelos Teóricos , Plantas/anatomia & histologia , Plantas/genética , Vertebrados/anatomia & histologia , Vertebrados/genética
15.
Emerg Top Life Sci ; 8(1): 29-35, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38095549

RESUMO

Bacteria employ diverse mechanisms to manage toxic copper in their environments, and these evolutionary strategies can be divided into two main categories: accumulation and rationalization of metabolic pathways. The strategies employed depend on the bacteria's lifestyle and environmental context, optimizing the metabolic cost-benefit ratio. Environmental and opportunistically pathogenic bacteria often possess an extensive range of copper regulation systems in order to respond to variations in copper concentrations and environmental conditions, investing in diversity and/or redundancy as a safeguard against uncertainty. In contrast, obligate symbiotic bacteria, such as Neisseria gonorrhoeae and Bordetella pertussis, tend to have specialized and more parsimonious copper regulation systems designed to function in the relatively stable host environment. These evolutionary strategies maintain copper homeostasis even in challenging conditions like encounters within phagocytic cells. These examples highlight the adaptability of bacterial copper management systems, tailored to their specific lifestyles and environmental requirements, in the context of an evolutionary the trade-off between benefits and energy costs.


Assuntos
Bactérias , Cobre , Análise Custo-Benefício , Evolução Biológica , Simbiose
16.
Microb Genom ; 10(1)2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38175684

RESUMO

Reference-based alignment of short-reads is a widely used technique in genomic analysis of the Mycobacterium tuberculosis complex (MTBC) and the choice of reference sequence impacts the interpretation of analyses. The most widely used reference genomes include the ATCC type strain (H37Rv) and the putative MTBC ancestral sequence of Comas et al. both of which are based on a lineage 4 sequence. As such, these reference sequences do not capture all of the structural variation known to be present in the ancestor of the MTBC. To better represent the base of the MTBC, we generated an imputed ancestral genomic sequence, termed MTBC0 from reference-free alignments of closed MTBC genomes. When used as a reference sequence in alignment workflows, MTBC0 mapped more short sequencing reads and called more pairwise SNPs relative to the Comas et al. sequence while exhibiting minimal impact on the overall phylogeny of MTBC. The results also show that MTBC0 provides greater fidelity in capturing genomic variation and allows for the inclusion of regions absent from H37Rv in standard MTBC workflows without additional steps. The use of MTBC0 as an ancestral reference sequence in standard workflows modestly improved read mapping, SNP calling and intuitively facilitates the study of structural variation and evolution in MTBC.


Assuntos
Mycobacterium tuberculosis , Humanos , Mycobacterium tuberculosis/genética , Coma , Fluxo de Trabalho , Genômica , Filogenia
17.
JAMA Ophthalmol ; 142(1): 33-38, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38095891

RESUMO

Importance: Fireworks can cause vision-threatening injuries, but the association of local legislation with the mitigation of these injuries is unclear. Objective: To evaluate the odds of firework-related ocular trauma among residents of areas where fireworks are permitted vs banned. Design, Setting, and Participants: This case-control study was conducted at a level 1 trauma center in Seattle, Washington, among 230 patients presenting with ocular trauma in the 2 weeks surrounding the Independence Day holiday, spanning June 28 to July 11, over an 8-year period (2016-2022). Exposures: Firework ban status of patient residence. Main Outcomes and Measures: Odds of firework-related injuries among residents of areas where fireworks are legal vs where they are banned, calculated as odds ratios (ORs) and 95% CIs. Results: Of 230 consultations for ocular trauma during the study period, 94 patients (mean [SD] age, 25 [14] years; 86 male patients [92%]) sustained firework-related injuries, and 136 (mean [SD] age, 43 [23] years; 104 male patients [77%]) sustained non-firework-related injuries. The odds of firework-related ocular trauma were higher among those living in an area where fireworks were legal compared with those living in an area where fireworks were banned (OR, 2.0 [95% CI, 1.2-3.5]; P = .01). In addition, the odds of firework injuries were higher for patients younger than 18 years (OR, 3.1 [95% CI, 1.7-5.8]; P < .001) and for male patients (OR, 3.3 [95% CI, 1.5-7.1]; P = .004). Firework injuries were more likely to be vision threatening (54 of 94 [57%]) compared with non-firework-related injuries (54 of 136 [40%]; OR, 2.1 [95% CI, 1.2-3.5]; P = .01). Conclusions and Relevance: This case-control study suggests that the odds of firework-related ocular trauma were slightly higher among residents of areas where fireworks were legal compared with residents of areas where fireworks were banned. Although these results suggest that local firework bans may be associated with a small reduction in the odds of firework-related ocular trauma, additional studies are warranted to assess what actions might lead to greater reductions.


Assuntos
Traumatismos por Explosões , Traumatismos Oculares , Humanos , Masculino , Adulto , Traumatismos por Explosões/epidemiologia , Traumatismos por Explosões/prevenção & controle , Traumatismos por Explosões/complicações , Estudos de Casos e Controles , Traumatismos Oculares/epidemiologia , Traumatismos Oculares/etiologia , Férias e Feriados , Estudos Retrospectivos
18.
bioRxiv ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38617210

RESUMO

Pathogenic Leptospira are spirochete bacteria which cause leptospirosis, a re-emerging zoonotic disease of global importance. Here, we use a recently described lineage of environmental-adapted leptospires, which are evolutionarily the closest relatives of the highly virulent Leptospira species, to explore the key phenotypic traits and genetic determinants of Leptospira virulence. Through a comprehensive approach integrating phylogenomic comparisons with in vitro and in vivo phenotyping studies, we show that the evolution towards pathogenicity is associated with both a decrease of the ability to survive in the environment and the acquisition of strategies that enable successful host colonization. This includes the evasion of the human complement system and the adaptations to avoid activation of the innate immune cells. Moreover, our analysis reveals specific genetic determinants that have undergone positive selection during the course of evolution in Leptospira, contributing directly to virulence and host adaptation as demonstrated by gain-of-function and knock-down studies. Taken together, our findings define a new vision on Leptospira pathogenicity, identifying virulence attributes associated with clinically relevant species, and provide insights into the evolution and emergence of these life-threatening pathogens.

19.
Evol Dev ; 15(5): 344-64, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24074280

RESUMO

Heterochrony is an important mechanism in the evolution of amphibians. Although studies have centered on the relationship between size and shape and the rates of development, ossification sequence heterochrony also may have been important. Rigorous, phylogenetic methods for assessing sequence heterochrony are relatively new, and a comprehensive study of the relative timing of ossification of skeletal elements has not been used to identify instances of sequence heterochrony across Amphibia. In this study, a new version of the program Parsimov-based genetic inference (PGi) was used to identify shifts in ossification sequences across all extant orders of amphibians, for all major structural units of the skeleton. PGi identified a number of heterochronic sequence shifts in all analyses, the most interesting of which seem to be tied to differences in metamorphic patterns among major clades. Early ossification of the vomer, premaxilla, and dentary is retained by Apateon caducus and members of Gymnophiona and Urodela, which lack the strongly biphasic development seen in anurans. In contrast, bones associated with the jaws and face were identified as shifting late in the ancestor of Anura. The bones that do not shift late, and thereby occupy the earliest positions in the anuran cranial sequence, are those in regions of the skull that undergo the least restructuring throughout anuran metamorphosis. Additionally, within Anura, bones of the hind limb and pelvic girdle were also identified as shifting early in the sequence of ossification, which may be a result of functional constraints imposed by the drastic metamorphosis of most anurans.


Assuntos
Anfíbios/crescimento & desenvolvimento , Osteogênese , Anfíbios/fisiologia , Animais , Evolução Biológica , Metamorfose Biológica , Filogenia
20.
Rev Fish Biol Fish ; : 1-22, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37360578

RESUMO

Developed countries are increasingly dependent on international trade to meet seafood requirements, which has important social, environmental, and economic implications. After becoming an independent coastal state following Brexit, the UK faces increased trade barriers and changes in seafood availability and cost. We compiled a long-term (120-year) dataset of UK seafood production (landings and aquaculture), imports, and exports, and assessed the influence of policy change and consumer preference on domestic production and consumption. In the early twentieth century, distant-water fisheries met an increasing demand for large, flaky fish such as cod and haddock that are more abundant in northerly waters. Accordingly, from 1900 to 1975, the UK fleet supplied almost 90% of these fish. However, policy changes in the mid-1970s such as the widespread establishment of Exclusive Economic Zones and the UK joining the European Union resulted in large declines in distant-water fisheries and a growing mismatch between seafood production versus consumption in the UK. While in 1975, UK landings and aquaculture accounted for 89% of seafood consumed by the British public, by 2019 this was only 40%. The combination of policy changes and staunch consumer preferences for non-local species has resulted in today's situation, where the vast majority of seafood consumed in the UK is imported, and most seafood produced domestically is exported. There are also health considerations. The UK public currently consumes 31% less seafood than is recommended by government guidelines, and even if local species were more popular, total domestic production would still be 73% below recommended levels. In the face of climate change, global overfishing and potentially restrictive trade barriers, promoting locally sourced seafood and non-seafood alternatives would be prudent to help meet national food security demands, and health and environmental targets.. Supplementary Information: The online version contains supplementary material available at 10.1007/s11160-023-09776-5.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA